MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - MGBGT respray problem

Just had my ’79 MGBGT resprayed by a reputable and established (club recommended) classic car restorer. It was returned to me last week by trailer (had to be transported because I’d removed all glass, trim, lights, bumpers, etc) and I was ready to start finishing it off with all the new parts I’ve bought. The first thing I noticed were lots of tiny scratches all over the paint surface. Touching the surface with my finger just added more scratches, and any attempt to polish them out (with T-cut, Brasso, etc) just made it worse. It seems that the paint hasn’t cured/hardened – it’s still soft. I did a fingernail test (on the C-post by the roof weld, an area which will be covered by the ‘GT’ trim) and pushed my thumbnail into the paint. This has left a very deep depression, probably the full thickness of the paint. I did this fingernail test 17 days after their respray guy put on the top coat and I would have expected it to have hardened by then. See the attached photos which show the thumbnail test and area of the front wing (these are all close-up shots covering an area about 2 inches wide).

I phoned the spray shop and spoke to the boss who seems quite concerned. He wants to come out to have a look at the car (I’m over an hour’s drive from the sprayshop) and bring the painter with him, although this can’t be arranged anytime soon because he’s off on holiday ‘til the end of next week. He phoned the paint suppliers and the only suggestion they had was that maybe the 3 coats of paint (4 coats on some panels) will take longer to harden.

I visited the restorers when the job was a day or two off being finished, when some of the panels had been flatted and buffed/polished and it looked ok although tiny scratches were visible. The painter assured me that these would all be polished out by the time he’d finished with it. I don’t think the scratches will ever polish out until the paint is fully hardened.

I would appreciate any advice, such as what may have caused this paint to stay soft, and also how to deal with these guys when they come to see the car. It’s obvious to me that something’s gone wrong with the paint job but I may need to get expert advice/opinion to back me up if I need to press them to rectify the job.

Brief description of the main work done at the paint shop:

The body was found to be in excellent condition throughout. Most panels were just flatted ready to receive primer or top coat. Lower front wings and a small part of the doors were taken down to bare metal and primed. Top coated with Pro-Spray direct gloss (nearly 4 litres used). Whole car was then hand flatted and buffed, machine glazed twice, and hand polished. Total time taken by painter: 11 days.


Brian Shaw

Result of thumbnail pressure

Brian Shaw

Front wing

Brian Shaw

Front wing 2

Brian Shaw

Brian,
me thinks someone made a mistake and has not put his hand up :0)
A quick check of the pro-spray web site suggests the paint should be dry overnight in good weather and less in a heated spray booth. The tests you have carried out also suggest the description of work done has not been carried out! eg "hand flatted and buffed". Me thinks not! If you can scratch it by touching it it clearly hasn't been buffed!
I suggest you print out the paint technical date sheet to use as a reference in your conversation but the bottom line is it all needs to come off and start again.

MGmike
M McAndrew

Hi, the issue is most definately with the paint, more likely the ratio of hardener that was mixed (or not).
S Taylor

Brian-
I do my own paint jobs. The painter skimped on the hardener. It'll all have to be removed and redone from scratch.
Stephen Strange

Thanks for the comments so far.

I've looked up the Pro-Spray website and noted that they specify 3 parts + 1 part 'activator'. The paint shop boss thought there may have been some reaction between the original paint and the paint they applied, but I checked the panel that had been sanded down to bare metal and that suffers from the same defect.

Stephen/S Taylor, you've confirmed my suspicion that the problem has been caused by whoever mixed the paint.
Does it really all have to be removed? I'm just anticipating what these guys might suggest to rectify this (at minimal cost to themselves of course) when I (hopefully) get them to visit next week - I think they may try to get me to settle for flatting down and spraying a coat or two of correcty mixed paint on top, which would leave me with a hard layer of paint on top of a soft layer .....
Brian Shaw

Brian, contact the paint supplier for a solution.
Art Pearse

While paint may take a few weeks to months to fully "cure" modern paints are ready for wet sanding fairly soon after painting. Most shops use heat to accelerate the drying time.

With paint as soft as yours, I don't believe you could do a good finish sanding and buffing.

I also feel someone screwed up and did not mix the paint systems as they should. Or, they used different components. I have seen shops use good quality paint and then another manufacturers thinner, hardener, catalyst etc. Sometimes, these are not as compatible.
Bruce Cunha

Brian that's dreadful and not to be accepted. My roadster was sprayed in water based colour and 2 pack lacquer. The lacquer was as soft as s**t. It was returned and re-baked, which made no difference at all. So I presume it was just inferior product. In the end I had it re-done with a known, top notch, lacquer. This produced a serviceable finish, although not as bullet proof as the 2 pack paint I used on the inside and under bonnet. I don't think lacquer can ever be as hard as paint because of the lack of "solids" in it's make up.
Allan Reeling

Brian, this sounds horribly familiar. I had an MGB heritage shell sprayed and it was still 'nail markable' 6 weeks on. Paint shop contacted supplier and they admitted a 'duff batch' of hardner. I didn't really want the shell stripped chemically and so they flatted it back to primer, re-sprayed it and baked it at a higher temp than before. Obviously some interior areas are not perfect, but the outside is. Mine was weird, you could put a finger nail mark in it one night and it was gone (sort of healed) in the morning. Make sure they correct it at their expense and liaise direct with the paint supplier. I also gave them a test piece off the car - the fuse box plate which I removed anyway and they tried flatting and re-finishing in several areas to check which went hard. Just re-coating DID NOT work !!!
Andrew Walton

Andrew, your story sounds very similar to what's happened with my car. The day after the fingernail test I noted that it had virtually self-healed. When the ambient temperature was below 10C my nail would hardly leave a mark. After a few minutes warming the panel up with a hairdryer the panel could be easily marked.

I don't think I'll accept anything less than complete removal of all the paint they've put on, but there could be difficulties flatting it all off because some panels still have original paint directly underneath the new top coat so they won't know when they're down to the original 'good' paint.

When you talk about 'paint supplier' do you mean the trade outlet that mixes the paint to the required colour and sells it to the paint shop, or the manufacturer of the various paint system components (in my case Pro-Spray)?
Brian Shaw

Brain,
don't think, insist on total removal and not just what they put on but right back to bare metal because you just can't be sure how much they leave behind. Insist on being present to inspect BEFORE the first coat goes back on to ensure they do as instructed. It'll be worth the day off work.

MGmike

M McAndrew

MGmike, yes I'll be keeping a close watch on all rectification work; fortunately I retired years ago and can visit them every day, although they are not local - my other transport (also an MGB) is a bit sick at the moment so instead of a 75 minute drive it'll be a three and a half hour each way bus/rail commute.
Brian Shaw

Brian, I wanted to kill dead any arguements about it was the paint, it was the sprayer !! So I got the paint manufacturer to the workshop and let them go for it!! Then when we had a conclusion I told them what I wanted done. BTW charge them for all travel to and fro to the sprayshop. This is a re-spray, not a trip to Mars and it should be within the capability of any reputable shop to get it right. Good luck - let us know how it goes. I'll test mine again inside today, it's now been 3 years and see if it has finally hardened !!!
Andrew Walton

Andrew, you say the paint supplier 'admitted a duff batch of hardener' - what made them finally confess to this? Did they analyse a paint sample or find that others were having the same problem with their paint/hardener?

It's 4 weeks since the paint job and still no improvement. The paint shop boss is back on Monday so hopefully some action next week.

Brian Shaw

Brian,

Your opening post implied you have a connection (membership?) of a Club. I suggest you investigate the possibility of having a knowledgeable Club member (friend) present when the shop visits. If you or other Club members have connections into other car clubs, a knowledgeable member from one of those also present sends a message to the shop reps about consequences if they don't get this solved reasonably.

Regards
Roger
Roger T

Brian, Good luck next week. It was quite simple, the sprayer was convinced it wasn't him and so asked the paint manu to come and mix some up, sprayed it and it did the same !! I was there for the confession! Several other vehicles sprayed with the same batch of hardner had to be re-called. Suggest some test pieces sprayed with the mix used on the car.
Andrew Walton

It was all worth it though - see attached !!!

Andrew Walton

Thanks Andrew and Roger for the latest advice. Nice car!

Andrew, the paint shop have now had a couple of weeks (holiday) to think up some reason/excuse for the paint problem. If they suggest the paint may be faulty, then test pieces painted with the same mix (as you describe) may prove useful.

Roger, I am a member of both the main MG clubs in the UK although I've had no involvement at local level due to too many other commitments and hobbies; I will, however make contact with them to see if there is a knowledgeable local member. The paint shop that refinished my car is a 'recommended supplier' of one of the clubs; they have achieved this status purely by way of feedback from club members, and this was the main reason for me entrusting them with my car, even though their estimate for the work was much higher than that of my local paint shop. The club handbook contains some useful advice on how to proceed when restoration work is of a poor standard, and I shall be following their advice when dealing with this paint shop. If things get difficult, the club handbook states that they will mediate between member and supplier if necessary.
Brian Shaw

It seems you are not alone with being unhappy with Club recommendations. I wonder how much vetting goes on, or is it like Trip advisor where hotels can post their own glowing revues.

http://www.youtube.com/watch?v=SJJ2RACHXm8

I've insisted on poor quality bodywork being rectified, albeit with insurance repairs, I sent one car back three times before I was happy. And that was after I initially signed, accepting the work.
c cummins

This thread was discussed between 24/09/2012 and 08/10/2012

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now